Surveying instrument



R. ROOT.

Surveying Instrument. 7 No. 26,621. Patehted Dec. 21, 1859.

N. Film MUM WMM'QQ as seen in Fig. 2.

UNITED STATES PATENT; OFFICE. f

RILEY R OOT, OF GALESBURG, ILLINOIS.

SURVEYING INSTRUMENT.

Specification of Letters Patent No. 26,621, dated December 27', 1859.

To all whom it may concern:

Be it known that I, RILEY ROOT, of Galesburg, in the county of Knox and State of Illinois, have invented a new and useful instrument, called a diamadrant, designed for civil engineering andtaking astronomical observations; and I do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being had to the annexed drawings, making a part of this specification, in which Figure 1, is a side view of the instrument, Fig. 2, is a vertical View of the double spirit level.

Reference letter A, represents the plate to which are attached a graduated half circle, the double spirit level, the sights, or telescope, as the case may be, and the axle, around which the plate revolves. B, a grad uated circle; C, a double spirit level; D, the sights; E, the axle, F, the double spirit level Respecting the dimensions of the instrument no definite size need be named. The

plate may be from 10 to 14 inches in length,

and the circle from 6 to 10 inches in diameter, as suits the pleasure of the occupant.

The instrument is designed as an attachment to a surveyors compass, and can be placed over it, or at the side of it, as seen by the drawing, but its legitimate use cannot be The double spirit level serves two purposes. It is not only used as a level, but as an index, to point to the degree of elevation.

The level or index is made to move over the whole of the graduated scale, so that in using 1 the instrument, the level must always be. i

placed on the lowest endfof the graduated l half circle, exceptwhena level line is :tobe. f taken, and in that case it makes no difference. v1 1 .50 I it is necessary only,to set the instrument and direct the sights to the north star atthe C proper time of observation, and elevate the spirit level to a horizontalpositionyand the 1 degree on which the index rests, is the lati.

Therefore toobtain. the. latitude of a place,

tude of the place.

For the survey of a railroad, the field notes are best arranged as follows,

so i

13651 Elevations or depressions in railroad sur- 1 veys, need notbe taken infect with thls 1n;

strument, as isusual with a transit-,althouglr that method may be pursued if desired. 3

Having now described the instrument and:

the mode of using it, I do not claim eithera horizontal or vertical graduated circle for 1 the purpose of determining the degrees of radiated lines, nor theuse of a single spiriti level, but

What I do claim as myjinvention, and de- I sire to'secure by LettersPatent, is

The arrangement of a revolving: double spirit level adapted tova graduatd circle as. a seen in the drawing andset forth1 inlthe specifications forastronomical and engineer i 1nur oses. I I

g p p RILEY ROOT.

Witnesses: 1 j I L. H. FUL ER, SQF. STEELE. 

